Link found between osteoarthritis and fibromyalgia pain

Researchers at the University of Manchester have uncovered brain abnormalities that could be behind the chronic pain suffered by osteoarthritis patients.

The study, funded by Arthritis Research UK, suggests the need for new therapies to target brain mechanisms to help the mind cope more effectively with chronic pain.

Up to 30% of the population could be affected by chronic pain at any one time, with arthritis leading to the most common complaints of pain. As the pain spreads to other areas, patients can become more disabled and find it difficult to cope as the condition disrupts sleep and other normal daily routines.

“The extent of pain experienced by sufferers of arthritis has always been thought to result from the direct consequences of joint destruction. However the extent of pain is often poorly related to the amount of damage and can spread to nearby regions of the body where there is no evidence of arthritic disease. We wanted to look at what might be causing this,” said Professor Anthony Jones, from The University of Manchester’s Human Pain Group based at Salford Royal Foundation Trust.

Researchers looked to see whether there was a link between the pain suffered by arthritis and fibromyalgia suffers.

Previous studies have suggested that fibromyalgia patients suffer from abnormalities in the way that the brain deals with pain. The Manchester team looked for overlaps in the way that pain is processed in the brain by osteoarthritis and fibromyalgia sufferers to understand why some people feel pain more acutely than others.

The study, published in the European Journal of Neuroscience, measured brainwaves in response to short painful laser pulses to the skin of patients suffering from osteoarthritic and fibromyalgia pain, as well as test subjects who had no underlying pain. Scientists discovered that the insula cortex part of the brain increased its activity when expecting a painful pulse, as it predicts the extent and intensity of the patients’ own chronic pain.

“Increased activity in this brain area has been linked to a number of phenomena, including body perception and emotional processing, which might explain the greater pain perception in some patients,” said Dr Christopher Brown, Honorary Research Associate, Human Pain Research Group, The University of Manchester.

“Interestingly, responses during pain anticipation were reduced in an area at the front of the brain called the dorsolateral prefrontal cortex. These reduced responses corresponded to less ability to develop positive ways of coping with the pain in both groups of patients.

“We think that boosting activity either directly or indirectly in this area of the brain is likely to result in better coping and better control of pain responses in other areas of the brain.”

The research suggests that there is a link between the way in which the brain expects pain in sufferers of fibromyalgia and osteoarthritis.